Heating and cooling are among the main causes of pollution and climate change. I wanted to find the most interesting green solutions applicable not only to villas or residences but also to condominiums and hospitality.
Today I propose the topics I am studying myself and the sources I am using. This is important information if you want to consider changes in the heating or cooling systems for your business, your home or more generally to understand what options are currently available.
Topics covered in this article
– The current situation and global and Italian targets;
– Green solutions for heating;
– Green solutions for cooling;
Curiosities about condominium rules and the Italian law of 2011 (scattered information).
Green solutions: the current situation and global and Italian objectives
Despite improvements in recent years, there is still a long way to go to meet global sustainable energy targets.
About 50% of the energy
50% of the energy used worldwide today is for heat production and this is responsible for 40% of energy-related greenhouse gas emissions, as well as significant levels of air pollution that threaten the environment and public health.
Source: ARPAT and article on puntosicuro.it
The seventh sustainable development target of the 2030 Agenda is CLEAN AND ACCESSIBLE ENERGY.
The goal is to ensure that everyone has access to affordable, reliable, sustainable and modern energy systems.
The energy transition aims to cut greenhouse gas emissions from the energy sector, which alone produces three-quarters of global emissions. According to the International Energy Agency (and Net Zero by 2050 report), 90% of the energy that powers global economies will have to be produced from renewable sources by 2050. The path outlined in the report is long and challenging. It sets out 400 milestones to be reached and surpassed over a 30-year period. The article The future of emissions and society according to the energy transition by Francesco Suman, a science journalist, summarises the changes we will see and that will have to be made to stay within this path. Changes that I personally am looking forward to. As a businesswoman, however, I am afraid of discovering the reality of the situation, of the choices to be made for my hotel, of the compromises between ownership and management that we will have to make, and of the constant sensation of being, as a hospitality business, always a little behind our colleagues in other countries if these steps are not made mandatory by law.
In Italy, there are far too many documents that set targets for renewables: the PNRR (National Recovery and Resilience Plan), the PNIEC (National Integrated Energy and Climate Plan, to be updated), the National Long-Term Strategy on the reduction of greenhouse gas emissions.
To reach the 2030 targets we will have to install about 70 GW of renewables in the next 10 years, which means installing about 7 GW per year, but last year we were at about 0.8 GW.
What happened to pollution during the 2020 lockdown?
Traffic pollution has decreased, thanks to the total traffic stop decided by the government, i.e. private cars, company cars and vehicles of all sizes.
A drastic reduction in nitrogen dioxide (NO2) emissions was immediately observed. After an initial timid reduction recorded at the beginning of March 2020, especially in the cities of central and northern Italy, the figures for particulate emissions (pm 2.5 and pm 10) have risen again.
The problem is attributable both to the effect of high atmospheric pressure, which has allowed the air in the lower layers to stagnate, favouring the accumulation of pollutants and to the widespread use of domestic heating.
Emissions of pm 10 linked to heating systems fuelled by woody biomass, such as fireplaces and pellet stoves, are also on the rise.
Green heating solutions
Traditional heating methods consist of using fossil fuels: coal, oil and natural gas. Not only are the costs of collecting these fossil fuels high, but so is the damage they cause to the environment.
According to Energy Star reports, geothermal heating is the most environmentally friendly and efficient way to heat your home. However, this requires an upfront investment in a geothermal heating system. Other interesting solutions are pellet stoves, masonry stoves and of course solar thermal heating.
Here is some more information.
- Geothermal heating literally means ‘heat from the earth’ and uses the constant temperature of the earth to heat rooms. The geothermal heating system is installed below the earth’s surface where the temperature is higher than the outside air. This means that it takes less energy to reach the temperature set on the thermostat.
- Pellet stoves use pellets made from renewable sources such as waste products like sawdust from sawmills. These products are transformed into small, fairly cheap pellets. In Italy, pellet stove flue gases cannot be discharged through the wall, but only through the roof, so they must be channelled into a chimney.
- It is no secret that solar heating is the most energy efficient heating solution. The most important decision to make is which type of solar heating system you want to install. The first type heats the liquid in a hydronic collector while the second heats the air. In most cases, the decision is based on the type of heating system you have.
- Masonry stove. Similar to pellet stoves, the masonry stove is a much smaller compact heating solution that looks more like a traditional fireplace. However, masonry stoves are slightly different from both a traditional wood-burning fireplace and a pellet stove. A masonry heater actually traps heat within the bricks of the twisted smoke chambers providing heat for up to 24 hours. Although masonry heaters burn wood, they produce less pollution than a traditional wood stove because they burn more slowly. Because of the slow combustion and trapped heat, masonry heaters produce more heat than other types of stoves and fireplaces.
Information taken from the article written for mymove.com by journalist Shelley Little.
Cooling, cooling and other green solutions
We live in an increasingly hot world. According to the US National Aeronautics and Space Administration (NASA), 2020 was the hottest year on record, with the average global temperature about 1.03 degrees Celsius (°C) higher than the average for the late 19th century (Barbosa 2021). The year 2021 just ended was only the sixth and together the past eight years have been the warmest since modern temperature recording began in 1880.
Today’s space cooling practices are generally very energy intensive and rely heavily on fossil fuels, generating electricity and climate-damaging refrigerants.
The UNEP report Beating the Heat: A Sustainable Cooling Handbook for Cities, the subject of my study, suggests an approach for cities starting with understanding the diversity between rural and urban areas.
The strategy consists of 3 areas:
- Reducing heat at the urban scale
- Reducing cooling needs in buildings
- Meeting the cooling needs of buildings efficiently.
Actions for the objective of reducing heat at the urban scale are:
*Exploiting the cooling benefits of open green spaces and water bodies. Land use distribution and planning should include the provision of green spaces and water bodies to mitigate urban heat.
- Properly directed wind flow can remove excess heat and polluted air away from urban communities and help maximise the movement of fresh air from natural sources. It is therefore advisable to align and orient (new) buildings to the prevailing winds.
- The management and reduction of waste heat generated by human activities, such as industrial processes, is an important part of addressing urban cooling. Some actions include appropriate land use zoning for industrial areas, requiring waste heat to be reused on site or in multiple collective systems such as heating or cooling networks, improving public transport and/or vehicle regulations to reduce heat.
- Cooling benefits can come through evapotranspiration and direct shade in the case of trees and other vegetation. Consequently, the integration of vegetation into the urban fabric can reduce temperature with good possibilities for integrating urban greenery and water features.
- A shift towards reflective urban surfaces for buildings and pavements can make cities cooler by reducing the amount of heat that is transmitted from the earth’s surface and trapped in the city air. Higher solar reflectance increases the % of light reflected back from the earth’s surface.
A hypothetical ‘cool communities’ programme in Los Angeles predicted – two decades ago – that urban temperatures could be reduced by about 3°C after planting 10 million trees, re-roofing 5 million homes and painting a quarter of the streets; the estimated cost would be $1 billion, giving estimated annual benefits of $170 million from reduced air-conditioning costs and $360 million in smog-related health savings, a simple payback period of less than two years (Rosenfeld et al. 1997).
Reducing cooling needs in buildings
Strategies for the design of passively cooled buildings can impact on urban cooling in interrelated ways:
- reducing overall heat gain and heat island effects (through appropriate materials and surfaces);
- reducing the cooling load (and related emissions) in buildings;
- reducing waste heat through reduced cooling mechanics.
Key passive cooling principles that help reduce mechanical cooling loads in buildings include:
- a building orientation appropriate to the climate;
- appropriate materials and design features in the building envelope, including insulation, windows and shading, to minimise heat gain due to thermal transmittance; natural ventilation (where temperature, humidity and air quality allow);
- thermal mass to stabilise internal temperatures.
Mandatory or voluntary energy codes for buildings are the means to guide passive cooling strategies in buildings. Code adoption is common in developed economies such as the European Union and the United States and the positive results are recognised and appreciated.
However, in most developing countries, the adoption and implementation of building energy codes to deliver the benefits of thermally efficient buildings remains low.
Although passive cooling strategies are generally easier and cheaper to incorporate during new construction, thus avoiding a significant part of future cooling demand, they can also apply to (and benefit) existing buildings, especially during renovation and reuse.
Although the theoretical potential of creating energy codes is promising and well documented, there are a number of barriers to implementation and enforcement: institutional challenges, regulatory challenges, lack of enabling mechanisms to create and sustain markets, low stakeholder motivation due to split incentives, and lack of awareness and capacity.
Some passive cooling strategies particularly suitable for existing buildings include installing high performance windows, adding insulation, adding shading devices and implementing cool roofs.
The third strategy in the whole systems approach concerns all means and solutions designed to minimise the energy and emission footprint of cooling.
Key solutions include:
- Controls and sensors: The use of controls and sensors can help eliminate the use of equipment that causes cooling (and energy) losses.
- Depending on the size of the building served, equipment can range from simple – such as a thermostat – to very complex and geographically distributed sensors that can control various processes and groups of buildings.
Controls and sensors using cooling include:
- detection of demand between zones using thermostats, occupancy sensors and air quality sensors;
- modulation of supply to meet demand by providing the right cooling and delivering it only to the spaces that require it (examples include variable air volume, variable refrigerant flow and variable speed motors or inverters).
User adaptations and behavioural changes:
Consumers are often unaware of the amount of energy consumed by cooling equipment. This lack of awareness – sometimes coupled with low electricity costs – gives consumers very little incentive to improve and manage their cooling use. However, by promoting energy-saving behaviour everyone can reduce energy consumption without sacrificing comfort, health or productivity.